Thomas a



(No Model.) 7

T. .A. EDISON;

MEANS FOR CHARGING AND USING SECONDARY BATTERIES.

No. 435,687. Patented Sept. 2, 1890.

Wpemtom UNITED STATES THOMAS A. EDISON, OF MENLO PARK, NEW'JERSEY, ASSIGNOR Torus P ATENT OFFICE.

EDISON ELECTRIC LIGHT COMPANY, OF- NEW YORK,

MEANS FOR CHARGING AND ,usme SECONDARY BATTERIES.

SPECIFICATION forming part of Letters Patent No. 435,687, dated September 2, 1890. i Application filed September 3, 1881. Serial No. 41,326. (No model.) Patented in England October 18, 188 1, No. 4,553, and'in To all whom, it may concern:

Be it known that I, THOMAS A. EDISON, of Menlo Park, in the County of Middlesex and State of New Jersey, have invented a new and useful Improvement in Secondary-Bat tery Systems, of which the following is a source of electricity for electric lights or other Fig; 2 1s a diagram illustrating that form in translating devices. To accomplish this I provide, in connection with the secondary batvceries, an-adj ustable auxiliary source of elec-' tricity, and by connecting this source with the circuit and adj nsting its electro-motive force at the proper times I maintain constantthe current supplied from the batteries- Such auxiliary source maybe a dynamo-electric generator provided with means for regulating its electromotive force, or it may be composed of auxil-' iary secondary cells provided withsuitable switches for bringing them into circuit at the proper times.

My invention is illustrated in the' accoinpanying drawings. b

Figure 1 is a diagram illustrating iny invention where a dynamo-electric machine is used.

which extra secondary cells are used.

Referring, first, to Fig. 1, C'and 13' each represent a series of secondary cells or accumulators 1315. .These series of cells are connected in multiple arc with main conductors12, with which conductors electric lamps or other translating devices A-A are. connected in multiple arc. The connection of the batteries with conductorl is made by means of conductors 4 and 5 through the armature of the dynamo-electric machine E, so

that said inachinevis in series with the batteries. The field-magnet of the machine is preferably connectecha's' shown, through wires 0 and 7, in shuntto the armature. Said fieldcircuitcon-tains a series of resistance-coils F, which fare placed in or out of circuit by adjusting the pivoted switch-arm d. Itwiil be France December 17. 1881, in. 146,736.

understood that the cells are of suchxcapacity that when charged theywill give therequired electiomotii e force to operate the translating devices. The currentfrom the cell B, passing to the main conductors 1 it, will pass through'the armature of the generator E; but such generator is not operated while the electro-mot-ive force-of thebattery remains practically constant, but upon a c rtain predetermined drop in the pressure from the main conductors, which may be shown by a suite .able indicator provided for the purpose, the engine that drives the generator E is started while all the resistance-coils F are inthe fieldcircuit. The generator thus causes to pass through the coils a weakcurrent sufficient to re-enforce'the battery current and -to re-establish the desired pressure, although the batteries themselves will still supply the principal part of the current. cator shows another drop of thecurrent, the switch-arm (Z is moved to out out part of the resistance of the field-circuit of the generator E, whereby the strength of its field-magnet will be increased and the electro-motive force I of the generator will be raised and the current supplied to conductors 1 2 will be brought up again to the required pressure. Other sections of the resistance are cut out as required from time to'tim e, the power of increase of the dynamo electric machine being adapted for the work to be done, so that the electro-motive force can bemaintained without fall the desired time. Vhen the batteries are exhausted, they may be recharged and used. over again in the same way. I prefer to provide each series of cells with a switch casothat either:

or both of the series maybe used at anytime.

In the arrangement shown in Fig. 2 the secondary cells Bare arranged in series K, L, and M, each series being connected independently of the others to main conductor 1. At the endsof the series they are connected together by cross-wires 8, 9, 10, and 11, each of which When the indiincludes one more cell of each series than the" next cross-wire to the left. The wires'8, 9, 10,

said switch being connected by a wirelf. with 1 main conductor 9.. At the beginning of the operation of the cellsswitchf is in contactwith wire 11 and the normal current is given by the cells on theleft thereof. As the electro-motive force drops, contact is made successively with wires 10, 9, and 8, whereby additional cells are successively added to the series and the electro-motive force of each series is maintained practically constant. a

It will be understood that the secondary cells B are charged in any suitable manner and are disconnected from the chargin gsource before being used in connection with the. translating devices.

I do not claim herein the specific arrangement illustrated in Fig. 2 of the drawings, since I propose to embody this in a separate application.

W hat I claim is- 1. The combination, with secondary batteries and translating devices supplied thereby, of a variable auxiliary source of electricityfor re-cnforcingsaid batteries as their electro-motive force decreases, substantially as set forth. f

2. The combination, with secondary batteries and translating devices supplied thereby, of a dynamo-electric machine provided with means for regulating its electro-motlre force for roe-enforcing said batteries as theneIcctro-motive force decreases, substantially as set forth. a 3. The combination, with secondary batteries and translating devices supplied therefrom, ofa dynamo-electric machine connected in series with said batteries and provided with means for regulating its clectro-motn e I force forre-cliforoing-said batteries as their 'clectro-rnotivc force decreases, substantially as set forth.

21st day of June, 1881.

THOS. A. EDISON. Witnesses:

WM. H. MEADow RoFLu MAURICE J. CnAGET'r.

This specification signed and witnessed this 

